Re: Ansoft mesh generation

Yehuda D. Yizraeli (yehuda@chipx.co.il)
Sun, 10 Nov 96 15:05:06 IST

Dear Wai-Yeung Yip,

Without touching the issues raise, first, let me ask you some questions
i am asking myself. Why are u using the Ansoft programm..? Is it history which
made u use this S/W or its the best in the market for such jobs. Without looking
at the support u are getting/not getting. Pure techicaly, how do u rate this
S/W. Do u know of other S/W packages for the job, what are they, Vendors and how
do u rate those compared to Ansoft..?

If so, u have the SW, what do u mean by poor support, what do u compare
it for, getting from other vendors...?


I am in the middle of deciding whats the second SW package i will
evaluate compared to Ansoft and any data from you, or any other engineer doing
such analysis, will be welcomed with THANKS THANKS..... and many more.





best regards, yehuda


>
> To the expert Ansoft users out there,
>
> I am doing a lot of BGA modeling using the Ansoft Maxwell 3D and Quick 3D
> software programs, and I routinely run into mesh generation problems. I am not
> getting satisfactory support from Ansoft and so any tricks I can learn from
you
> would be very helpful. Usually the program fails to even generate the initial
> mesh. With the Maxwell 3D program I cannot get into using seeded mesh without
> first having the initial mesh generated. So I have to resort to putting dummy
> objects in the solution space to help the meshing. Have you any suggestions as
> to what objects to use? I usually enclose what I consider problematic part of
> the conductors with boxes but this does not always work.
>
> Even if I succeed in getting the initial mesh, the magnetic field solver may
> still fail. In this case I have to do seeded mesh. Do you have suggestions as
to
> what seed values to use? Based on my experience, with too large seed values,
the
> mesh generator may fail, or even it does not, the magnetic field solver may
> still fail. With too small seed values, I end up with too many elements and I
> run out of memory before I can do enough passes to get a converged solution.
>
> Another problem I run into is when I have extrusions and I need to compute a
> port inductance matrix for de-embedding, the port inductance solver may fail.
> This happens despite the fact that I have already got a converged 3D
inductance
> solution and so the mesh is supposedly adequately fine. Any workarounds?
>
> Thank you very much in advance for your assistance.
>
> Regards,
> Wai-Yeung Yip
> LSI Logic
>

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